Tubular conductor-in-slot connecting device

ABSTRACT

Conductor-in-slot connecting device comprises a first formed tubular member having an axially extending open seam and having sidewalls on each side of the seam. A second tubular member is formed from material in the sidewalls of the first tubular member and has a second open seam. When wire is moved laterally of its axis and into both of the open seams, the edges of the second tubular member penetrate the insulation of the conductor and establish electrical contact with the conducting core. The edges of the first tubular member penetrate the insulation only and function as a strain relief for the conductor.

United States Patent Shoemaker TUBULAR CONDUCTOR-IN-SLOT CONNECTING DEVICE [75] Inventor: John Robert Shoemaker, Walkerton,

[73] Assignee: AMP Incorporated, Harrisburg, Pa.

[22] Filed: Oct. 12, 1973 [21] Appl. No.: 405,970

[52] US. Cl. 339/97, 339/103 C [51] Int. Cl H01r 9/06 [58] Field of Search 339/95, 96, 97, 98, 99, 339/103, 104

[56] References Cited UNITED STATES PATENTS 2,873,434 2/l959 Drum et al 339/97 C 3,147,058 9/[964 Zdanis 339/97 R 3,634,605 1/l972 Nola 339/98 3,683,319 8/l972 Vigeant et al 339/97 R Primary Examiner-Paul R. Gilliam Assistant Examiner-Robert A. Hafer Attorney, Agent, or FirmFrederick W. Raring; Jay L. Seitchik; William J. Keating [5 7] ABSTRACT Conductor-in-slot connecting device comprises a first formed tubular member having an axially extending open seam and having sidewalls on each side of the seam. A second tubular member is formed from material in the sidewalls of the first tubular member and has a second open seam. When wire is moved laterally of its axis and into both of the open seams, the edges of the second tubular member penetrate the insulation of the conductor and establish electrical contact with the conducting core. The edges of the first tubular member penetrate the insulation only and function as a strain relief for the conductor.

8 Claims, 5 Drawing Figures TUBULAR CONDUCTOR-lN-SLOT CONNECTING DEVICE BACKGROUND OF THE INVENTION This invention relates to conductor-in-slot connecting devices of the general type shown in application Ser. No. 347,956 filed Apr. 4, 1973. That application discloses and claims an improved multi-contact electrical connector having a plurality of terminals therein, each terminal having a tubular portion at one end which has an axially extending open seam. To connect a conductor to a terminal in the connector, it is merely necessary to move the conductor laterally of its axis and into the open seam so that the edges of the seam penetrate the insulation of the conductor and establish electrical contact with the conducting core thereof. The multi-contact connector shown in application Ser. No. 347,956 also has a back cover for its housing which functions as a strain relief for the conductors so that if a tensile force is applied to a conductor, the force will not be transmitted to the electrical connection between the conductor and the connecting device.

It has been recognized that it would be desirable to provide a connecting device of the tubular type having all of the advantages of the connecting device of application Ser. No. 347,956 and also having an integral strain relief for the conductor. The present invention is directed to the achievement of such an integral strain relief means for a tubular conductor-in-slot connecting device.

It is accordingly an object of the invention to provide an improved conductor-in'slot connecting device having a strain relief for the conductor. A further object is to provide a tubular conductor-in-slot connecting device which can be used under a wide variety of circumstances, for example, as a free standing connecting device on a printed circuit board or as the wire connecting portion of a terminal in a multi-contact electrical connector. A further object is to provide a tubular connecting device which is so formed that it is resistant to damage prior to its being put to use (during handling and shipping) and after it is put to use.

These and other objects of the invention are achieved in one preferred embodiment thereof which is briefly described in the foregoing abstract, which is described in detail below, and which is shown in the accompanying drawing in which:

FIG. 1 is a perspective view of a portion of a printed circuit board having connecting devices in accordance with the invention mounted thereon. FIG. 2 is a perspective view of one of the connecting devices shown in FIG. 1.

FIG. 3 is a frontal view of the connecting device prior to insertion of a conductor into its conductor slots.

FIG. 4 is a view similar to FIG. 3 but showing a single wire inserted into the slots.

FIG. 5 is a view taken along the lines 5-5 of FIG. 4.

The herein disclosed embodiment of the invention comprises a stamped and formed connecting device 2 which is adapted to be mounted on a printed circuit board 8 to connect insulated wires 4 to conductors 6 on the upper or lower sides of the board. The connecting device comprises a first tubular member 10 having a web 12 and sidewalls 14 which extend parallel to each other from the web and which are bent inwardly and towards each other at 16 to define an axially extending open seam generally indicated at 17. The seam has an entry portion 18 and an intermediate relatively wide intermediate portion 20 which defines downwardly facing (as viewed in FIG. 3) shoulder 21. The lower portion of the seam is simply sheared as shown at 23 and prior to insertion of the wire, there is no gap between the opposed edges as there is in the upper and intermediate portions 18, 20 of the seam.

A second tubular member 22 is formed from material struck from the sidewalls 14 of the first tubular member 10 and this second tubular member has sidewalls 24 which are curved inwardly and towards each other as shown at 26. In the disclosed embodiment, there is a narrow gap between the edges of the seam which may be of the same width of that of the entry portion 18 of the seam in the outer tubular member. The width of this gap is less than the diameter of the conducting core 5 of the wire so that the edges of the seam (which serves as a wire-receiving slot) will penetrate the insulation of the wire and establish electrical contact with the conducting core.

1n the disclosed embodiment, the sidewalls 24 are sheared as shown at 30 on each side of the seam at two spaced-apart locations, these shear lines extending lateraliy away from the slot to punched holes 32 which serve to reduce perpetration of cracks into the sidewalls from the ends of the shear lines. As explained in application Ser. No. 347,956, these transverse shears divide the second tubular member into three separate spring systems so that a conductor can be positioned in each one of these spring system and will not be effected by a conductor in an adjacent spring system.

It will be noted that the shoulder 31 at the lower end of the intermediate portion 20 of the seam or slot in the first tubular member 10 is co-planar with the lower-end of the second tubular member 22. By virtue of this fact, an individual wire 4 cannot be moved downwardly past the lower most spring system of the second tubular member. In other words, the conductor cannot be moved downwardly to the extent that it would be moved out of the second tubular member.

The disclosed embodiment of the invention has downwardly extending feet 34 which project from its sidewalls 14 to facilitate mounting in holes in the printed circuit board and soldering to the conductors of the board. As mentioned previously, connecting devices in accordance with the invention can also be used as part of a contact terminal, for example, of the type shown in the above-identified application Ser. No. 347,956 and can be used under many other circumstances.

In use, and after the connecting devices 2 have been mounted on the printed circuit board 8, the insulated wires 4 are merely moved laterally of their axes into the wire-receiving slots of the first and second tubular members 10,22. When an individual wire is initially moved into a connecting device, the end portion of the wire will move into the conductor receiving slot (the open seam) of the first tubular member 10. The sidewalls 14 of the first tubular member form a relatively light spring system because of the fact that they are, relatively wide and additionally because of the fact that the central portions of these sidewalls have been removed to form the second tubular member 22. The first tubular member 14 thus constitutes a light spring system which will yield or flex outwardly during insertion of the wire. The second tubular member 22 on the other hand, constitutes a relatively stiff spring system so that the edges of the sidewalls will penetrate the insulation and establish electrical contact with the core when the wire is moved into the wire receiving slot (the open seam) of the second tubular member.

After the wire has been fully inserted, the insulation of the wire will be held between the edges of the slot of the portion of the first tubular member and the electrical connection of the core of the wire to the connecting device will be at the edges of the slot in the second tubular will be as shown in H0. 5. If a tensile pull is applied to the wire 4, it will be transmitted to the terminal through the outer or first tubular member 14 and will largely bi-pass the electrical connection between the second tubular member and the conducting core.

If a wire located in the upper part of the intermediate slot portion 20 is pulled upwardly, the shoulder 21 will resist movement of the wire therepast and the lower shoulder 31 will, as noted above, prevent movement of a wire past the lower end of the second tubular member 22.

Connecting devices in accordance with the invention can be made in relatively small sizes for printed circuit board applications as shown. For example, good results have been obtained with the connecting device formed from No. 4 hard cartridge brass having a thickness of 0.012 inch and having a height (between the ends of the tubular member 14) of 0.275 inch. Larger connecting devices can be made in accordance with the invention if desired and the dimensions presented above do not necessarily represent the smallest connecting device which can be produced in accordance with the invention.

A salient advantage of the invention is that an integral strain relief for the conductor is provided as discussed above. It should also be noted that the inner tubular member is surrounded by the first tubular member 14 so that the first tubular member protects the second tubular member against damage during handling and after the terminal is put to use. The inter tubular member 22 is more susceptible to damage since the width of its slot must be held to relatively close tolerances while the outer tubular member can be abused to some extent during handling without the loss of its function.

While the drawing shows a wire connected to the connecting device, it will be apparent that other types of conductors can be connected to the device, for example, a flat ribbon-like conductor as shown in application Ser. No. 310,056 or a conductor in a ribbon cable.

Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only.

What is claimed is:

1. ln a stamped and formed connecting device comprising a first formed tubular member having a first axially extending open seam, said first seam serving as a first conductor-receiving slot having opposed edges whereby upon movement of a conductor laterally of its axis and into said first slot, said edges engage said conductor, the improvement to said device comprising:

a second tubular member having a second axially extending open seam which is in alignment with said first open seam in said tubular member, said second tubular member and said first tubular member having a common bight portion, and said second tubular member having side portions which are struck from side portions of said first tubular member, said second tubular member being contained within said tubular member each said side portion of each said tubular membenbeing bent towards its opposing side portion at its free end, said free ends thus forming said conductor receiving slots, whereby upon movement of a conductor laterally of its axis into said first open seam and said second open seam from one end of said device, said conductor is engaged by edge portions of both of said open scams.

2. A stamped and formed connecting device as set forth in claim 1, said first tubular member being geher ally rectangular in cross-section.

3. A stamped and formed connecting device as set forth in claim 2, said side portions of said second tubular member being arcuate.

4. A stamped and formed connecting device as set forth in claim 2, said first open slot having a relatively narrow entry portion at one end of said first tubular member and having an intermediate relatively wider portion, and a transversely extending shoulder between said entry portion and said intermediate portion whereby, said shoulder inhibits lateral movement of a conductor from said intermediate portion.

5. A stamped and formed connecting device as set forth in claim 4, said second tubular member having an inner end which is remote from said one end, and said intermediate portion of said first slot having an inner end which is remote from said entry portion, said inner ends being in alignment whereby said inner end of said intermediate portion prevents movement of a conductor beyond said inner end of said second tubular member.

6. A connecting device for forming an electrical and mechanical connection to an insulated conductor comprising:

first and second tubular members,

said first tubular member comprising a web and sidewalls, said sidewalls extending inwardly and towards each other, said first tubular member having a first axially extending open seam, said first open seam comprising a first conductor-receiving slot,

said second tubular member having a web and second sidewalls, said web of said second tubular member comprising an intermediate portion of the web of said first tubular member, said sidewalls of said second tubular member being struck from the sidewalls of said first tubular member, and said second tubular member having an axially extending open seam which is in alignment with said first axially extending open seam whereby,

upon locating a conductor beside one end of said connecting device with the axis of said conductor in alignment with said conductor-receiving slots, and upon movement of said conductors laterally of their axes and into said slots, said conductor will be received between the edges of both of said slots.

7. An electrical connection of a conductor to a connecting device, said connecting device comprising:

first and second tubular members,

6 said first tubular member comprising a web and sideserving as a second conductor-receiving slot,

walls, said sidewalls having marginal portions said conductor extending through said slots and towhich extend inwardly and towards each other, wards said web, said slots having edge portions in said first tubular member having a first axially exengagement with said conductor to mechanically tending open seam, said first open seam serving as 5 and electrically connect said conductor to said dea first conductor-receiving slot, vice. said second tubular member having a web and sec- 8. An electrical and mechanical connection as set 0nd sidewalls, said web of said second tubular forth in claim 7 wherein said conductor comprises an member comprising an intermediate portion of said insulated wire, said edge portions of said second slot web of said first tubular member, said sidewalls of 10 penetrating the insulation of said wire and being in said second tubular member being struck from said electrical contact with the metallic core of said wire,

sidewalls of said first tubular member, and said secsaid edges portion of said first slot penetrating the insuond tubular member having an axially extending lation of said wire whereby a mechanical strain relief is open seam which is in alignment with said first axiprovided for said wire.

ally extending open seam, said second open seam 

1. In a stamped and formed connecting device comprising a first formed tubular member having a first axially extending open seam, said first seam serving as a first conductor-receiving slot having opposed edges whereby upon movement of a conductor laterally of its axis and into said first slot, said edges engage said conductor, the improvement to said device comprising: a second tubular member having a second axially extending open seam which is in alignment with said first open seam in said tubular member, said second tubular member and said first tubular member having a common bight portion, and said second tubular member having side portions which are struck from side portions of said first tubular member, said second tubular member being contained within said tubular member each said side portion of each said tubular member being bent towards its opposing side portion at its free end, said free ends thus forming said conductor receiving slots, whereby upon movement of a conductor laterally of its axis into said first open seam and said second open seam from one end of said deVice, said conductor is engaged by edge portions of both of said open seams.
 2. A stamped and formed connecting device as set forth in claim 1, said first tubular member being generally rectangular in cross-section.
 3. A stamped and formed connecting device as set forth in claim 2, said side portions of said second tubular member being arcuate.
 4. A stamped and formed connecting device as set forth in claim 2, said first open slot having a relatively narrow entry portion at one end of said first tubular member and having an intermediate relatively wider portion, and a transversely extending shoulder between said entry portion and said intermediate portion whereby, said shoulder inhibits lateral movement of a conductor from said intermediate portion.
 5. A stamped and formed connecting device as set forth in claim 4, said second tubular member having an inner end which is remote from said one end, and said intermediate portion of said first slot having an inner end which is remote from said entry portion, said inner ends being in alignment whereby said inner end of said intermediate portion prevents movement of a conductor beyond said inner end of said second tubular member.
 6. A connecting device for forming an electrical and mechanical connection to an insulated conductor comprising: first and second tubular members, said first tubular member comprising a web and sidewalls, said sidewalls extending inwardly and towards each other, said first tubular member having a first axially extending open seam, said first open seam comprising a first conductor-receiving slot, said second tubular member having a web and second sidewalls, said web of said second tubular member comprising an intermediate portion of the web of said first tubular member, said sidewalls of said second tubular member being struck from the sidewalls of said first tubular member, and said second tubular member having an axially extending open seam which is in alignment with said first axially extending open seam whereby, upon locating a conductor beside one end of said connecting device with the axis of said conductor in alignment with said conductor-receiving slots, and upon movement of said conductors laterally of their axes and into said slots, said conductor will be received between the edges of both of said slots.
 7. An electrical connection of a conductor to a connecting device, said connecting device comprising: first and second tubular members, said first tubular member comprising a web and sidewalls, said sidewalls having marginal portions which extend inwardly and towards each other, said first tubular member having a first axially extending open seam, said first open seam serving as a first conductor-receiving slot, said second tubular member having a web and second sidewalls, said web of said second tubular member comprising an intermediate portion of said web of said first tubular member, said sidewalls of said second tubular member being struck from said sidewalls of said first tubular member, and said second tubular member having an axially extending open seam which is in alignment with said first axially extending open seam, said second open seam serving as a second conductor-receiving slot, said conductor extending through said slots and towards said web, said slots having edge portions in engagement with said conductor to mechanically and electrically connect said conductor to said device.
 8. An electrical and mechanical connection as set forth in claim 7 wherein said conductor comprises an insulated wire, said edge portions of said second slot penetrating the insulation of said wire and being in electrical contact with the metallic core of said wire, said edges portion of said first slot penetrating the insulation of said wire whereby a mechanical strain relief is provided for said wire. 